Lulu Liu, Wenrui Ma, Haolan Tan, Chuang Ge, Zhang Bei, Chunyan Wang, Yang Zhang, Yi Xu
The in-situ monitoring of quorum sensing (QS) signal molecules in bacterial biofilms was crucial for the diagnosis and treatment of bacterial biofilms. In this work, a surface-enhanced Raman scattering (SERS) chip integrated with functional units of bacterial biofilm cultivation and in-situ SERS detection was proposed for the monitoring of pyocyanine, an important signal molecule and biomarker secreted by Pseudomonas aeruginosa. The SERS chip was composed of a top self-assembled Nano-silver SERS substrate layer, a PDMS layer containing array micro-chambers and a bottom quartz layer. The Nano-silver SERS substrate showed good homogeneity and stability with the enhancement factor up to 1.84×108 for pyocyanine, and the design of SERS substrate located at the top layer of chip effectively attenuated the interference of complex matrix. In merit of the SERS chip, the detection limit for pyocyanine was as low as 1nM with a wide detection range of 1 nM~100 μM. The proposed SERS chip could achieve the monitoring of pyocyanine during the growth of Pseudomonas aeruginosa biofilms with and without treatment of different types anti-bacterial drugs. Furthermore, pyocyanine secreted by Pseudomonas aeruginosa were confirmed by mass spectrometry (MS) and the concentration relationship obtained by MS/MS was consistent with the SERS detection. The proposed method based on the SERS chip for monitoring QS in bacterial biofilms had advantages of in-situ detection, flexibility and efficiency.
{"title":"In-situ monitoring of Quorum Sensing signalling molecules by a SERS chip with array micro-chambers","authors":"Lulu Liu, Wenrui Ma, Haolan Tan, Chuang Ge, Zhang Bei, Chunyan Wang, Yang Zhang, Yi Xu","doi":"10.1039/d4an00992d","DOIUrl":"https://doi.org/10.1039/d4an00992d","url":null,"abstract":"The in-situ monitoring of quorum sensing (QS) signal molecules in bacterial biofilms was crucial for the diagnosis and treatment of bacterial biofilms. In this work, a surface-enhanced Raman scattering (SERS) chip integrated with functional units of bacterial biofilm cultivation and in-situ SERS detection was proposed for the monitoring of pyocyanine, an important signal molecule and biomarker secreted by Pseudomonas aeruginosa. The SERS chip was composed of a top self-assembled Nano-silver SERS substrate layer, a PDMS layer containing array micro-chambers and a bottom quartz layer. The Nano-silver SERS substrate showed good homogeneity and stability with the enhancement factor up to 1.84×108 for pyocyanine, and the design of SERS substrate located at the top layer of chip effectively attenuated the interference of complex matrix. In merit of the SERS chip, the detection limit for pyocyanine was as low as 1nM with a wide detection range of 1 nM~100 μM. The proposed SERS chip could achieve the monitoring of pyocyanine during the growth of Pseudomonas aeruginosa biofilms with and without treatment of different types anti-bacterial drugs. Furthermore, pyocyanine secreted by Pseudomonas aeruginosa were confirmed by mass spectrometry (MS) and the concentration relationship obtained by MS/MS was consistent with the SERS detection. The proposed method based on the SERS chip for monitoring QS in bacterial biofilms had advantages of in-situ detection, flexibility and efficiency.","PeriodicalId":63,"journal":{"name":"Analyst","volume":"17 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Based on the specific hydrolytic ability of alkaline phosphatase (ALP), a novel biocompatible ratiometric lanthanide fluorescent probe based on internal reference (CIP@SiO2-Ce/ATP-Tris) was constructed with Ce3+ as the central ion, adenosine triphosphate (ATP) as the ligand, Tris as the auxiliary ligand and ciprofloxacin (CIP) encapsulated into SiO2 nanoparticles as the reference signal. The fluorescent probe emits characteristic fluorescence at 363 nm belonging to Ce3+ as the working signal and at 435 nm belonging to CIP as the reference signal. Dephosphorylation disrupted the coordination of Ce/ATP-Tris with the enzymatic reaction of ALP, which resulted in a fluorescence quenching of Ce3+. The reference fluorescence was kept stable because of protective effect by encapsulated SiO2. The biosensor analysis method was achieved by comparing the relationship between I435/I363 and ALP concentration. The detection limit is 0.0025 U/L, and the linear range of detection is 0.1-20 U/L. It was subsequently used to detect ALP in samples of fetal bovine serum and human serum, and promising results were obtained.
{"title":"Novel Ratiometric Fluorescent Probe based on Internal Reference of Lanthanide/nucleotide for Alkaline Phosphatase Detection","authors":"Haoran Yu, Ziqing Qiang, Yelin Sun, Mengyao Sun, Lei Zhang, Bohao Yu, Wen Lei, Weibing Zhang","doi":"10.1039/d4an01341g","DOIUrl":"https://doi.org/10.1039/d4an01341g","url":null,"abstract":"Based on the specific hydrolytic ability of alkaline phosphatase (ALP), a novel biocompatible ratiometric lanthanide fluorescent probe based on internal reference (CIP@SiO<small><sub>2</sub></small>-Ce/ATP-Tris) was constructed with Ce<small><sup>3+</sup></small> as the central ion, adenosine triphosphate (ATP) as the ligand, Tris as the auxiliary ligand and ciprofloxacin (CIP) encapsulated into SiO<small><sub>2</sub></small> nanoparticles as the reference signal. The fluorescent probe emits characteristic fluorescence at 363 nm belonging to Ce<small><sup>3+</sup></small> as the working signal and at 435 nm belonging to CIP as the reference signal. Dephosphorylation disrupted the coordination of Ce/ATP-Tris with the enzymatic reaction of ALP, which resulted in a fluorescence quenching of Ce<small><sup>3+</sup></small>. The reference fluorescence was kept stable because of protective effect by encapsulated SiO<small><sub>2</sub></small>. The biosensor analysis method was achieved by comparing the relationship between I<small><sub>435</sub></small>/I<small><sub>363</sub></small> and ALP concentration. The detection limit is 0.0025 U/L, and the linear range of detection is 0.1-20 U/L. It was subsequently used to detect ALP in samples of fetal bovine serum and human serum, and promising results were obtained.","PeriodicalId":63,"journal":{"name":"Analyst","volume":"1 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142684575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiaoya Liu, Hai Peng, Lisha Gong, Hong Zhang, Chenglong Zhao, Weiju Lai, Gang An, Xianxian Zhao
Cardiovascular disease, intimately linked to dyslipidemia, is one of the leading global causes of mortality. Dyslipidaemia often presents as an elevated concentration of low-density lipoprotein (LDL) and a decreased concentration of high-density lipoprotein (HDL). Therefore, accurately measuring the levels of LDL and HDL particles is crucial for assessing the risks of developing cardiovascular diseases. However, conventional approaches can commonly quantify HDL/LDL particles by detecting the cholesterol or protein molecules within them, which possibly fail to report the amounts of intact particles. In addition, these approaches are sometimes tedious and time-consuming, therefore, highlighting the need for a novel method for precise and effective identification of intact HDL and LDL particles. We have devised a technique that allows accurately and sensitively determining the levels of intact HDL and LDL in a sample without the need for isolation. This method relies on antibody-based immobilization and a self-priming hairpin-triggered Cas12a/crRNA signaling strategy. Based on the elegant design, this technique can be employed to directly and precisely measure the concentration of “actual” HDL and LDL particles, rather than the cholesterol content inside HDL and LDL. The approach has detection limits of 12.3 mg/dL and 5.4 mg/dL for HDL and LDL, respectively, and is also suitable for analyzing lipoproteins in clinical samples. Hence, this platform exhibits immense potential in clinical applications and health management.
{"title":"Reliable and Precise Lipoprotein Detection based on the Self-Priming Hairpin-Triggered Cas12a/crRNA based Signaling Strategy","authors":"Xiaoya Liu, Hai Peng, Lisha Gong, Hong Zhang, Chenglong Zhao, Weiju Lai, Gang An, Xianxian Zhao","doi":"10.1039/d4an01167h","DOIUrl":"https://doi.org/10.1039/d4an01167h","url":null,"abstract":"Cardiovascular disease, intimately linked to dyslipidemia, is one of the leading global causes of mortality. Dyslipidaemia often presents as an elevated concentration of low-density lipoprotein (LDL) and a decreased concentration of high-density lipoprotein (HDL). Therefore, accurately measuring the levels of LDL and HDL particles is crucial for assessing the risks of developing cardiovascular diseases. However, conventional approaches can commonly quantify HDL/LDL particles by detecting the cholesterol or protein molecules within them, which possibly fail to report the amounts of intact particles. In addition, these approaches are sometimes tedious and time-consuming, therefore, highlighting the need for a novel method for precise and effective identification of intact HDL and LDL particles. We have devised a technique that allows accurately and sensitively determining the levels of intact HDL and LDL in a sample without the need for isolation. This method relies on antibody-based immobilization and a self-priming hairpin-triggered Cas12a/crRNA signaling strategy. Based on the elegant design, this technique can be employed to directly and precisely measure the concentration of “actual” HDL and LDL particles, rather than the cholesterol content inside HDL and LDL. The approach has detection limits of 12.3 mg/dL and 5.4 mg/dL for HDL and LDL, respectively, and is also suitable for analyzing lipoproteins in clinical samples. Hence, this platform exhibits immense potential in clinical applications and health management.","PeriodicalId":63,"journal":{"name":"Analyst","volume":"1 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wang Yang, Wanchen Xie, Chongtao Zhang, Fang Duan, Shuanglong Lu, Mingliang Du
Excessive residues of nitrite can pose a serious threat to human health, making the establishment of an efficient and effective electrochemical sensor for nitrite detection highly necessary. Herein, we report on a sensor based on nitrogen-doped carbon nanofibers, with FeCoNiCuAl high-entropy alloy (HEAs) nanoparticles in situ grown on the carbon fibers through a confinement effect. The FeCoNiCuAl/CNFs sensor is capable of electrochemically detecting nitrite using both differential pulse voltammetry (DPV) and amperometric (I-t) methods. The DPV detection offers a linear range of 0.1-5000 μM and 5000-18000 μM, with sensitivities of 150.6 μA mM-1 cm-2 and 80.1 μA mM-1 cm-2, and a detection limit of 0.023 μM (S/N=3). The I-t detection covers a range of 1-10000 μM, with a sensitivity of 337.84 μA mM-1 cm-2 and a detection limit of 0.12 μM. Moreover, the sensor exhibits excellent anti-interference properties, stability, and reproducibility, providing feasibility for nitrite detection in real-world environments.
{"title":"Nanofibers Decorated with High-Entropy Alloy Particles for the Detection of Nitrites","authors":"Wang Yang, Wanchen Xie, Chongtao Zhang, Fang Duan, Shuanglong Lu, Mingliang Du","doi":"10.1039/d4an01246a","DOIUrl":"https://doi.org/10.1039/d4an01246a","url":null,"abstract":"Excessive residues of nitrite can pose a serious threat to human health, making the establishment of an efficient and effective electrochemical sensor for nitrite detection highly necessary. Herein, we report on a sensor based on nitrogen-doped carbon nanofibers, with FeCoNiCuAl high-entropy alloy (HEAs) nanoparticles in situ grown on the carbon fibers through a confinement effect. The FeCoNiCuAl/CNFs sensor is capable of electrochemically detecting nitrite using both differential pulse voltammetry (DPV) and amperometric (I-t) methods. The DPV detection offers a linear range of 0.1-5000 μM and 5000-18000 μM, with sensitivities of 150.6 μA mM-1 cm-2 and 80.1 μA mM-1 cm-2, and a detection limit of 0.023 μM (S/N=3). The I-t detection covers a range of 1-10000 μM, with a sensitivity of 337.84 μA mM-1 cm-2 and a detection limit of 0.12 μM. Moreover, the sensor exhibits excellent anti-interference properties, stability, and reproducibility, providing feasibility for nitrite detection in real-world environments.","PeriodicalId":63,"journal":{"name":"Analyst","volume":"26 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142673200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper proposes a microfluidic chip for on-site radiation risk evaluation using immunofluorescence staining for the DNA double-strand break (DSB) marker phosphorylated histone, H2AX (γ-H2AX). The proposed microfluidic chip separates lymphocytes, the cells of the DNA DSB evaluation target, from whole blood based on their size and traps them in the trap structure. The subsequent DNA DSB evaluation, γ-H2AX assay, can be performed on a chip, which saves space and simplifies the complicated operation of the assay, which conventionally requires a large experimental space. Therefore, this chip will enable the biological effect evaluation of radiation exposure to be completed on-site. Bead experiments with samples containing 10 μm and 27 μm diameter beads showed that the proposed chip introduced the sample into the flow channel only by centrifugal force and passively separated the two types of beads by the structure in the flow channel. In addition, bead experiments showed that isolated 10 μm diameter beads were trapped in more than 95% of the 1000 lymphocyte trap structures (LTSs). The feasibility of the proposed method for on-site radiation risk evaluation was demonstrated through cell-based experiments by performing the γ-H2AX assay in human lymphoblastoid TK6 cells. The experiment shows that LTSs in the flow channel are capable of trapping TK6 cells, and γ-H2AX foci which are markers of DNA DSBs are observed in the TK6 cells on the chip. Thus, the results suggest that the proposed microfluidic chip simplifies the γ-H2AX assay protocol and provides a novel method to perform the assay on-site, which is conventionally impracticable.
{"title":"A novel microfluidic chip for on-site radiation risk evaluation","authors":"Kenta Takahashi, Takahiro Tamura, Kosuke Yamada, Kaisei Suga, Yuri Aoki, Ryota Sano, Kentaro Koyama, Asako J. Nakamura, Takaaki Suzuki","doi":"10.1039/d4an00941j","DOIUrl":"https://doi.org/10.1039/d4an00941j","url":null,"abstract":"This paper proposes a microfluidic chip for on-site radiation risk evaluation using immunofluorescence staining for the DNA double-strand break (DSB) marker phosphorylated histone, H2AX (γ-H2AX). The proposed microfluidic chip separates lymphocytes, the cells of the DNA DSB evaluation target, from whole blood based on their size and traps them in the trap structure. The subsequent DNA DSB evaluation, γ-H2AX assay, can be performed on a chip, which saves space and simplifies the complicated operation of the assay, which conventionally requires a large experimental space. Therefore, this chip will enable the biological effect evaluation of radiation exposure to be completed on-site. Bead experiments with samples containing 10 μm and 27 μm diameter beads showed that the proposed chip introduced the sample into the flow channel only by centrifugal force and passively separated the two types of beads by the structure in the flow channel. In addition, bead experiments showed that isolated 10 μm diameter beads were trapped in more than 95% of the 1000 lymphocyte trap structures (LTSs). The feasibility of the proposed method for on-site radiation risk evaluation was demonstrated through cell-based experiments by performing the γ-H2AX assay in human lymphoblastoid TK6 cells. The experiment shows that LTSs in the flow channel are capable of trapping TK6 cells, and γ-H2AX foci which are markers of DNA DSBs are observed in the TK6 cells on the chip. Thus, the results suggest that the proposed microfluidic chip simplifies the γ-H2AX assay protocol and provides a novel method to perform the assay on-site, which is conventionally impracticable.","PeriodicalId":63,"journal":{"name":"Analyst","volume":"178 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142673204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jianjing Shen, Li Yan, Jun Pang, Zhenyu Chu, Ying Xie, Shan Huang, Xiaojun Chen
The ratiometric sensing strategy with dual-signal output drastically compensates for the background noise and interference from the detection environment of the sensing method with a single-signal output. However, the stability of the reference signal has become the primary challenge in constructing a ratio detection sensor. Therefore, in order to realize stable ratio signal sensing detection, methylene blue (MB) was encapsulated in the UiO-66-NH2 framework and printed as a reference signal inside a screen printed carbon electrodes (SPCE), which was helpful for the precise detection of miR-21-5p. Subsequently, based on the ultra-sensitive detection mechanism of catalytic hairpin assembly (CHA), the combination of miR-21-5p with H1 sequence on the Au-deposited SPCE triggered the loop-open of H1. After that, ferrocene labeled H2 (H2-Fc) and H3-Fc sequences were sequentially added to form a stable “T-shaped” structure, and miR-21-5p was released into the next cycle. Thus, the detection of miR-21-5p was quantified by the current ratio of Fc with MB, obtaining a ultra-low detection limit of 2.7 fM. This ratiometric sensing strategy based on SPCE offered a promising pathway for the highly sensitive sensing platforms.
双信号输出的比率检测策略极大地补偿了单信号输出检测方法的背景噪声和检测环境干扰。然而，参考信号的稳定性已成为构建比率检测传感器的首要挑战。因此，为了实现稳定的比值信号传感检测，在 UiO-66-NH2 框架中封装了亚甲基蓝（MB），并将其作为参考信号印制在丝网印刷碳电极（SPCE）内，这有助于精确检测 miR-21-5p。随后，基于催化发夹组装（CHA）的超灵敏检测机制，miR-21-5p与H1序列结合在金沉积的SPCE上，触发了H1的开环。随后，二茂铁标记的 H2（H2-Fc）和 H3-Fc 序列依次加入，形成稳定的 "T "形结构，miR-21-5p 被释放到下一个循环中。因此，miR-21-5p 的检测是通过 Fc 与 MB 的电流比进行量化的，从而获得了 2.7 fM 的超低检测限。这种基于 SPCE 的比率测量传感策略为高灵敏度传感平台提供了一种前景广阔的途径。
{"title":"Mechanically Stabilized UiO-66-NH2-MB Screen Printed Carbon Electrode for High Performance Electrochemical Ratiometric Quantification of miR-21-5p†","authors":"Jianjing Shen, Li Yan, Jun Pang, Zhenyu Chu, Ying Xie, Shan Huang, Xiaojun Chen","doi":"10.1039/d4an01302f","DOIUrl":"https://doi.org/10.1039/d4an01302f","url":null,"abstract":"The ratiometric sensing strategy with dual-signal output drastically compensates for the background noise and interference from the detection environment of the sensing method with a single-signal output. However, the stability of the reference signal has become the primary challenge in constructing a ratio detection sensor. Therefore, in order to realize stable ratio signal sensing detection, methylene blue (MB) was encapsulated in the UiO-66-NH2 framework and printed as a reference signal inside a screen printed carbon electrodes (SPCE), which was helpful for the precise detection of miR-21-5p. Subsequently, based on the ultra-sensitive detection mechanism of catalytic hairpin assembly (CHA), the combination of miR-21-5p with H1 sequence on the Au-deposited SPCE triggered the loop-open of H1. After that, ferrocene labeled H2 (H2-Fc) and H3-Fc sequences were sequentially added to form a stable “T-shaped” structure, and miR-21-5p was released into the next cycle. Thus, the detection of miR-21-5p was quantified by the current ratio of Fc with MB, obtaining a ultra-low detection limit of 2.7 fM. This ratiometric sensing strategy based on SPCE offered a promising pathway for the highly sensitive sensing platforms.","PeriodicalId":63,"journal":{"name":"Analyst","volume":"251 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142673203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hannah Sheridan, Alexander Paul Dudgeon, John Day, Catherine A. Kendall, Charles Hall, Nick Stone
Fibre optic probe based Raman spectroscopy can deliver in vivo molecular compositional analysis of a range of diseases. However, some biological tissues exhibit high levels of fluorescence which limit the utility of the technique, particularly when the fluorescence induces CCD etaloning, which can be particulalry hard to remove in subsequent analysis. Furthermore, use of fibre probes can result in silica signals superimposed on the biological Raman signals. Shifted excitation Raman difference spectroscopy (SERDS) utilises a small seperation in excitation wavelengths to remove signals from fluorescence, room lights, optical components and etaloning contributions, while retaining chemical signals from the sample. In this study, we sought to measure the optimum SERDS spectra enabling reconstruction of a range a narrow and broad peaks found in biological samples. A original wavelength of 830 nm was utilised with 7 different shifts between 0.4 and 3.9 nm to determine which gave the best performance. This range roughly corresponds to the typical range of peak widths within biological Raman spectra at 830 nm excitation; 0.41 – 3.25 nm or 6 – 47 cm-1. An wavelength shift of 2.4 nm was identified as optimal. Finally, a fibre optic Raman probe was used to measure 2 human lymph nodes ex vivo to demonstrate the feasibility of the approach with real-world examples.
{"title":"Optimising Shifted Excitation Raman Difference Spectroscopy (SERDS) for application in highly fluorescent biological samples, using fibre optic Raman probes.","authors":"Hannah Sheridan, Alexander Paul Dudgeon, John Day, Catherine A. Kendall, Charles Hall, Nick Stone","doi":"10.1039/d4an01264j","DOIUrl":"https://doi.org/10.1039/d4an01264j","url":null,"abstract":"Fibre optic probe based Raman spectroscopy can deliver in vivo molecular compositional analysis of a range of diseases. However, some biological tissues exhibit high levels of fluorescence which limit the utility of the technique, particularly when the fluorescence induces CCD etaloning, which can be particulalry hard to remove in subsequent analysis. Furthermore, use of fibre probes can result in silica signals superimposed on the biological Raman signals. Shifted excitation Raman difference spectroscopy (SERDS) utilises a small seperation in excitation wavelengths to remove signals from fluorescence, room lights, optical components and etaloning contributions, while retaining chemical signals from the sample. In this study, we sought to measure the optimum SERDS spectra enabling reconstruction of a range a narrow and broad peaks found in biological samples. A original wavelength of 830 nm was utilised with 7 different shifts between 0.4 and 3.9 nm to determine which gave the best performance. This range roughly corresponds to the typical range of peak widths within biological Raman spectra at 830 nm excitation; 0.41 – 3.25 nm or 6 – 47 cm-1. An wavelength shift of 2.4 nm was identified as optimal. Finally, a fibre optic Raman probe was used to measure 2 human lymph nodes ex vivo to demonstrate the feasibility of the approach with real-world examples.","PeriodicalId":63,"journal":{"name":"Analyst","volume":"112 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142671113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Akhila Ajith, Emrys Jones, Emily Prince, Drupad Trivedi, Giles N Johnson, Phillip J Milnes, Nicholas Lockyer
Newer and safer agrochemicals are always in demand to meet the increasing needs of a growing population for affordable food. Spatial chemical monitoring of the active mobility of an agrochemical is essential to this agrochemical development process and mass spectrometry imaging (MSI) is proposed as a safer, easier alternative to the existing standard of autoradiography for the same. With desorption electrospray ionisation mass spectrometry Imaging (DESI MSI) using leaf imprints, we were able to visualize the active agrochemical mobility of a commercial fungicide formulation with the active ingredient Azoxystrobin in whole tomato leaves. The leaf-imprinting method was optimized with precise control over the pressure conditions and time of imprinting to yield highly consistent samples for imaging. The reproducibility of this method was tested with the Azoxystrobin formulation applied to tomato leaves and was compared to the mobility of the unformulated Azoxystrobin standard in similar application conditions. The xylem mobility and the lateral-leaf lamina spreading of the fungicide were visualized with mass spectrometry imaging and validated using complementary LC-MS studies. The necessity and importance of the agrochemical application as a formulation were re-iterated by the limited mobility observed in Azoxystrobin standard studies compared to the Azoxystrobin formulation. This mass spectrometry imprint-imaging method could be translated for the visualization of any xenobiotic in further foliar systems particularly with soft leaves.
{"title":"Visualizing active fungicide formulation mobility in tomato leaves with Desorption Electrospray Ionisation Mass Spectrometry Imaging","authors":"Akhila Ajith, Emrys Jones, Emily Prince, Drupad Trivedi, Giles N Johnson, Phillip J Milnes, Nicholas Lockyer","doi":"10.1039/d4an01309c","DOIUrl":"https://doi.org/10.1039/d4an01309c","url":null,"abstract":"Newer and safer agrochemicals are always in demand to meet the increasing needs of a growing population for affordable food. Spatial chemical monitoring of the active mobility of an agrochemical is essential to this agrochemical development process and mass spectrometry imaging (MSI) is proposed as a safer, easier alternative to the existing standard of autoradiography for the same. With desorption electrospray ionisation mass spectrometry Imaging (DESI MSI) using leaf imprints, we were able to visualize the active agrochemical mobility of a commercial fungicide formulation with the active ingredient Azoxystrobin in whole tomato leaves. The leaf-imprinting method was optimized with precise control over the pressure conditions and time of imprinting to yield highly consistent samples for imaging. The reproducibility of this method was tested with the Azoxystrobin formulation applied to tomato leaves and was compared to the mobility of the unformulated Azoxystrobin standard in similar application conditions. The xylem mobility and the lateral-leaf lamina spreading of the fungicide were visualized with mass spectrometry imaging and validated using complementary LC-MS studies. The necessity and importance of the agrochemical application as a formulation were re-iterated by the limited mobility observed in Azoxystrobin standard studies compared to the Azoxystrobin formulation. This mass spectrometry imprint-imaging method could be translated for the visualization of any xenobiotic in further foliar systems particularly with soft leaves.","PeriodicalId":63,"journal":{"name":"Analyst","volume":"76 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Björn van Marwick, Tim Kümmel, Felix Wühler, Felix Lauer, Jan Hoffmann, Matthias Rädle
The fast and reliable detection, segmentation and visualization of latent fingerprints are the main tasks in forensics. Currently, conventional fingerprints are searched for, recorded and subsequently analyzed via traditional destructive physical and chemical methods. For firmly defined crime objects and undefined crime scenes, the forensic process is very time-consuming and can take several hours for a single fingerprint. In this context, a laser-based measurement technique that records complete latent fingerprints under fifteen seconds in a non-destructive manner was developed that digitizes the fingerprint for postprocessing steps. The optical system is based on confocal measurements in the mid-infrared wavelength range (2 μm-4 μm) to analyze specific chemical substances at crime scenes. The resulting chemical segmentation allows molecule-dependent analysis of latent and visually invisible fingerprints, providing clear conclusions about the perpetrator or the course of the crime. In this study, the application of the developed measurement system (MIR scanner) to capture fingerprints in a molecule-dependent manner within few seconds is demonstrated, compared with reference methods such as FTIR (Fourier transform infrared spectroscopy) imaging, and extended to real crime objects.
{"title":"Rapid chemical detection and segmentation of latent fingerprints by means of a novel middle-infrared scanning method.","authors":"Björn van Marwick, Tim Kümmel, Felix Wühler, Felix Lauer, Jan Hoffmann, Matthias Rädle","doi":"10.1039/d4an00367e","DOIUrl":"https://doi.org/10.1039/d4an00367e","url":null,"abstract":"<p><p>The fast and reliable detection, segmentation and visualization of latent fingerprints are the main tasks in forensics. Currently, conventional fingerprints are searched for, recorded and subsequently analyzed <i>via</i> traditional destructive physical and chemical methods. For firmly defined crime objects and undefined crime scenes, the forensic process is very time-consuming and can take several hours for a single fingerprint. In this context, a laser-based measurement technique that records complete latent fingerprints under fifteen seconds in a non-destructive manner was developed that digitizes the fingerprint for postprocessing steps. The optical system is based on confocal measurements in the mid-infrared wavelength range (2 μm-4 μm) to analyze specific chemical substances at crime scenes. The resulting chemical segmentation allows molecule-dependent analysis of latent and visually invisible fingerprints, providing clear conclusions about the perpetrator or the course of the crime. In this study, the application of the developed measurement system (MIR scanner) to capture fingerprints in a molecule-dependent manner within few seconds is demonstrated, compared with reference methods such as FTIR (Fourier transform infrared spectroscopy) imaging, and extended to real crime objects.</p>","PeriodicalId":63,"journal":{"name":"Analyst","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142646537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dimple Saikia, Cebajel Bhanwarlal Tanan, G. Dhananjaya, Basavraj Hungund, Nilkamal Mahanta, Surya P. Singh
Colistin antibiotic is regarded as the final line of defense for treating infections caused by gram-negative bacteria. The combination of Raman spectroscopy (RS) with diverse machine learning methods has helped to unravel the complexity of various microbiology problems. This approach offers a culture-free, rapid, and objective tool for identifying antimicrobial resistance (AMR). In this study, we employed the combinatorial approach of machine learning and RS to identify a novel spectral marker associated with phosphoethanolamine modification in lipid A moiety of colistin resistant gram-negative Escherichia coli. The visible spectral fingerprints of this marker have been validated by partial least square regression and discriminant analysis. The origin of the spectral feature has been confirmed by hyperspectral imaging and K-means clustering of a single bacterial cell. The chemical structure of the modified lipid A moiety has been verified by gold standard MALDI-TOF mass spectrometry. Our findings support futuristic applicability of this spectroscopic marker in objectively identifying colistin-sensitive and resistant.
可乐定抗生素被视为治疗革兰氏阴性细菌感染的最后一道防线。拉曼光谱（RS）与多种机器学习方法的结合有助于解开各种微生物学问题的复杂性。这种方法为鉴定抗菌药耐药性（AMR）提供了一种无需培养、快速而客观的工具。在本研究中，我们采用了机器学习和 RS 的组合方法，以确定与耐可乐定革兰阴性大肠杆菌脂质 A 分子中磷乙醇胺修饰相关的新型光谱标记。该标记的可见光谱指纹已通过偏最小二乘法回归和判别分析进行了验证。该光谱特征的来源已通过高光谱成像和单个细菌细胞的 K-means 聚类得到证实。金标准 MALDI-TOF 质谱法验证了修饰脂质 A 分子的化学结构。我们的研究结果支持这一光谱标记在客观识别对可乐定敏感和耐药细菌方面的应用前景。
{"title":"Validating phosphoethanolamine modification as a potential spectral marker of colistin resistance","authors":"Dimple Saikia, Cebajel Bhanwarlal Tanan, G. Dhananjaya, Basavraj Hungund, Nilkamal Mahanta, Surya P. Singh","doi":"10.1039/d4an01228c","DOIUrl":"https://doi.org/10.1039/d4an01228c","url":null,"abstract":"Colistin antibiotic is regarded as the final line of defense for treating infections caused by gram-negative bacteria. The combination of Raman spectroscopy (RS) with diverse machine learning methods has helped to unravel the complexity of various microbiology problems. This approach offers a culture-free, rapid, and objective tool for identifying antimicrobial resistance (AMR). In this study, we employed the combinatorial approach of machine learning and RS to identify a novel spectral marker associated with phosphoethanolamine modification in lipid A moiety of colistin resistant gram-negative Escherichia coli. The visible spectral fingerprints of this marker have been validated by partial least square regression and discriminant analysis. The origin of the spectral feature has been confirmed by hyperspectral imaging and K-means clustering of a single bacterial cell. The chemical structure of the modified lipid A moiety has been verified by gold standard MALDI-TOF mass spectrometry. Our findings support futuristic applicability of this spectroscopic marker in objectively identifying colistin-sensitive and resistant.","PeriodicalId":63,"journal":{"name":"Analyst","volume":"12 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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